This invention relates to a method for recovering active benzo-c-phenanthridine alkaloids from plants containing these compounds.
Sanguinaria canadensis, Linn (family Papveracea) is commonly known as bloodroot, redroot, puccoon, teterwort, etc., and is a perennial herb native to North America. The plant and its juices have been used for various purposes in pre-historical and historical times. The plant has been used, in particular, as a folk remedy. The plant has generally been used whole, either undried (fresh) or dried. The usual procedure is to powder the dried plant and mix it with a carrier. This folk remedy has been tried for such conditions as asthma, bronchitis, dysentery, ringworm, and a substantial list of other ailments.
The principal use of Sanguinaria has been as a stimulant expectorant in cough syrups and in homeopathic medicine. In more recent years it has been used as an antiplaque agent in dentifrices and oral rinses.
An early patent, U.S. Pat. No. 209,331, discloses the use of bloodroot, zinc chloride, and kerosene oil in equal proportions for treating open sores. U.S. Pat. No. 433,257, describes a salve of pulverized bloodroot, armenian bole, powdered rosin, lard, and Stockholm tar for use in the treatment of piles. U.S. Pat. No. 2,344,830, discloses the use of a mixture of zinc chloride, stibnite, and bloodroot to fix and outline diseased tissue for excision by surgery.
More recently, it has been discovered that extracts of sanguinaria and other plants of the families Papaveraceae, Fumariaceae, and Berberidaceae such as Macleaya cordata, Macleaya Microcarpa, Bocconia frutescens, Corydalis sevctcozii, C. ledebouni, Argemone mexicanus, and Chelidonium majus contain benzo-c-phenanthridine alkaloids which are believed to have valuable properties in the control of dental plaque formation, conditioning oral tissue, as well as in preventing and treating gingivitis, periodontitis, and mouth odors.
The pure chemicals sanguinarine, chelerythrine, protopine, chelerubine, chelilutine, sanguilutine, macarpine, sanguirubine, allocryptopine, homochelidonene, and berberine, can be isolated from plants other than Sanguinaria. They are also available, although rarely, from some chemical supply houses. Semi-purified forms of the alkaloids are commercially available; these are generally referred to as sanguinarine nitrate and sanguinarine sulfate. These "salts" are the salts of the mixed alkaloids of the plant Sanguinaria: namely, sanguinarine, chelerythrine, and protopine. While few references can be found in the literature regarding the usage of any of the pure benzophenanthridine alkaloids, plants containing such compounds have been used for a wide variety of medical ailments.
Several patents have disclosed the use of extracts of Sanguinaria for such purposes, notably U.S. Pat. No. 4,145,412; U.K. Patent No. 2,042,336; U.S. Pat. No. 4,376,115; U.S. Pat. No. 4,406,881; German Offen. No. 2,907,406; Belgian patent No. 888,843. These patents describe the use of Sanguinaria extracts as antimicrobial agents as well as mouth treating agents.
The prior art cited above describes a method of extracting active ingredients from Sanguinaria canadensis by extracting out of ground bloodroot with methanol for at least 24 hours at an elevated temperature, filtering the liquid extract obtained, evaporating the extract to dryness, dissolving the dried residue in chlorofom, adjusting the chloroform solution to an acid pH by the addition of hydrochloric acid, filtering the acidified extract, evaporating it to dryness, and dissolving the dried residue in glycerine for mixing with a carrier.